L-Aspartic Acid CAS 56-84-8 (H-Asp-OH) Assay 98.5~101.0% Factory High Quality

L-Aspartic Acid, when dried, contains not less than 98.5% and not more than 101.0% of L-Aspartic Acid (C4H7NO4).
Description L-Aspartic Acid occurs as white, crystals orcrystalline powder. It is sparingly soluble in water, and practically insoluble in ethanol (99.5). It dissolves in dilute hydrochloric acid and in 0.2 mol/L sodium hydroxide TS.
Identification Determine the infrared absorption spectrum of L-Aspartic Acid as directed in the potassium bromide disk method under Infrared Spectrophotometry <2.25>, and compare the spectrum with the Reference Spectrum: both spectraexhibit similar intensities of absorption at the same wave numbers.
Optical rotation <2.49> [a]20D: +24.0~+26.0° (2 g, after drying, 6 mol/L hydrochloric acid TS, 25 mL, 100 mm).
pH <2.54> Dissolve 0.4 g of L-Aspartic Acid in 100 mL of water by warming, and allow to cool: between 2.5 and 3.5.
Purity (1) Clarity and color of solution-Dissolve 1.0 g of L-Aspartic Acid in 20 mL of 1 mol/L hydrochloric acid TS: the solution is clear and colorless.
(2) Chloride <1.03>-Dissolve 0.5 g of L-Aspartic Acid in 6 mL of dilute nitric acid and 20 mL of water, add water to make 50 mL, and perform the test with this solution as the test solution. Prepare the control solution with 0.30 mL of 0.01 mol/L hydrochloric acid VS (not more than 0.021%).
(3) Sulfate <1.14>-Dissolve 0.6 g of L-Aspartic Acid in5 mL of dilute hydrochloric acid and 30 mL of water, add water to make 45 mL, and add 5 mL of barium chloride TS. Perform the test with this solution as the test solution. Pre-pare the control solution with 0.35 mL of 0.005 mol/L sulfuric acid VS, add 5 mL of dilute hydrochloric acid and water to make 45 mL, and add 5 mL of barium chloride (not more than 0.028~).
(4) Ammonium<1.02>—Perform the test with 0.25 g of L-Aspartic Acid. Prepare the control solution with 5.0 mL of Standard Ammonium Solution (not more than 0.02z)
(5) Heavy Metals <1.07>-Proceed with 1.0 g of L-Aspartic Acid according to Method 4, and perform the test. Prepare the control solution with 1.0 mL of Standard Lead Solution (not more than 10 ppm).
(6)Iron <1.10>-Prepare the test solution with 1.0 g of L-Aspartic Acid according to Method 1, and perform the testaccording to Method A. Prepare the control solution with1.0 mL of Standard Iron Solution (not more than 10 ppm).
(7) Related Substances-Dissolve 0.20 g of L-AsparticAcid in 10 mL of 0.2 mol/L sodium hydroxide TS, and usethis solution as the sample solution. Pipet 1 mL of the sample solution, add water to make exactly 10 mL. Pipet 1 mLof this solution, add water to make exactly 50 mL, and use this solution as the standard solution. Perform the test with these solutions as directed under Thin-layer Chromatogra-phy<2.03>. Spot 5mL each of the sample solution and stand-ard solution on a plate of silica gel for thin-layer chromatog-raphy, develop with a mixture of 1-butanol, water and aceticacid (100) (3:1:1) to a distance of about 10 cm, and dry theplate at 809C for 30 minutes. Spray evenly a solution of nin-hydrin in a mixture of methanol and acetic acid (100) (97:3)(1 in 100), and heat at 80℃ for 10 minutes: the spot other than the principal spot obtained with the sample solution isnot more intense than the spot obtained with the standard solution.
Loss on Drying <2.41> Not more than 0.30% (1 g, 105℃,3 hours).
Residue on Ignition <2.44> Not more than 0.1% (1 g).
Assay Weigh accurately about 0.15 g of L-Aspartic Acid, previously dried, dissolve in 50 mL of water by warming. After cooling, titrate <2.50> with 0.1 mo/L sodium hydroxide VS (potentiometric titration). Perform a blank determination in the same manner, and make any necessary correction.
Each mL of 0.1 mol/L sodium hydroxide VS＝13.31 mg of C4H7NO4
Containers and storage Containers-Tight containers.